Although arrangements of the above-mentioned type in practice have the purpose of, between different wheel-supported units, such as cars and/or locomotives, in a train unit transferring not only tractive forces but also thrust forces, the same are commonly denominated “towing arrangements” by those skilled in the art. Characteristic of such towing arrangements is that the same include a bar or registration arm (usually in the form of a tube), which at a rear end in one way or the other is fixed in one of the ends of a frame included in the vehicle unit in question, and which at a front end is connected to one or more additional details while forming a coupler. For instance, the front end of the bar may be directly connected to a coupler head and together with the same form an automatic coupler, but it may also via a muff coupling or the like be connected to a collision protection, which in turn is connected to a coupler head. In the towing arrangement, means are also included in order to absorb shocks of moderate character, i.e., such shock motions that every day arise and are transferred between the vehicle units during travel as well as in connection with coupling of the vehicle units.